(AR15) SFFA V2 Select Fire Full Auto

(AR15) SFFA V2 Select Fire Full Auto Features

The SFFA V2 is packed with innovative features that set it apart in the realm of 3D-printed firearm components. Its primary function as a select-fire drop-in auto sear (DIAS) allows users to achieve full-auto firing with a standard MIL-SPEC AR15 fire control group (FCG), a rare and sought-after capability.

• Custom 3D Selector: Replace the standard selector with the provided 3D-printed version to unlock SAFE, SEMI, and FULL AUTO modes in that order.
• Fallback Compatibility: If the MIL-SPEC selector is retained, the DIAS operates in SAFE and FULL AUTO modes only, maintaining traditional functionality.
• Legal Design Consideration: Without the sear installed, the 3D selector defaults to SAFE, SEMI, SEMI, ensuring no hammer follow in the third position and remaining compliant in specific configurations.

This design prioritizes user safety and responsibility, with a clear disclaimer on the legal implications of creating a machine gun. Detailed documentation and an assembly animation on Odysee further enhance the user experience.

Difficulty & Build Time

• Skill Level: Intermediate
• Estimated Build Time: 6-8 hours
• Required Experience: Familiarity with AR15 fire control group assembly and 3D printing basics

Hardware and Tools Required

Required Hardware

• x1 Standard (MIL-SPEC) AR15 FCG (Avoid super safe cut triggers as they may cause full-auto in safe mode)
• x1 AR15 Bolt Catch Spring (For sear)
• x1 AR15 Bolt Catch Roll Pin (Cut down if using a non-M16 cut lower)

Note: Alternatively, remove the bolt catch from the lower to source non-printed parts, as it’s not required for operation.

Recommended Tools

• 3D Printer with a 0.4mm nozzle
• Cutting tools for roll pin modification (if needed)
• Basic hand tools for AR15 lower assembly
• Calipers for precise measurement during installation

(AR15) SFFA V2 Select Fire Full Auto Parts

The SFFA V2 file package includes meticulously designed STL files for the drop-in auto sear and custom selector, oriented correctly with brims and supports where necessary. STEP files are also provided, though not pre-oriented. Key updates like simplified housing, improved sear timing, and low-shelf housing designs ensure compatibility with various lowers.

Print settings are optimized for durability, with 100% rectilinear infill and 4 wall loops recommended for maximum strength. Recent change logs highlight enhancements like built-in supports for housing and no-support selector options, making printing more accessible. Check the "Other" folder for alternative versions like "No Support" housing or "No Brim" selector.

Printer Compatibility & Settings

The SFFA V2 is compatible with most FDM 3D printers equipped with a 0.4mm nozzle, ensuring broad accessibility for hobbyists. Recommended materials include PLA Pro for standard use or Polymaker PA6-CF for high-temperature applications, with specific settings available via the creator’s Odysee channel (@s3igu2).

• Temperature: 220°C (Nozzle) / 60°C (Bed) for PLA Pro
• First Layer Height: 0.20mm (or 0.15mm)
• Layer Height: 0.15mm
• Supports: Not required unless using specific "No Support" or "No Brim" versions from the "Other" folder

These settings ensure optimal print quality and structural integrity for functional use. Always refer to the detailed documentation for troubleshooting and material-specific guidance.

Conclusion

The (AR15) SFFA V2 Select Fire Full Auto is a game-changer for 3D printing and firearms enthusiasts, offering a rare select-fire capability with MIL-SPEC AR15 compatibility. With comprehensive documentation, updated designs, and accessible print settings, it’s a valuable addition to any FOSSCAD collection. Be sure to review the legal disclaimers, follow the assembly guide on Odysee, and approach this project with responsibility and caution.